Introduction

Ecological succession is a pivotal process in ecology, since it occurs in all dynamic systems. It is therefore hardly surprising that its study is still a major preoccupation of ecologists, though as one combs the past scientific literature there are clear fashions in areas of interest and the approach adopted. Thus, from early descriptions of specific successional patterns of the vegetation, attention turned to a consideration of the mechanisms underpinning succession and ways in which successional trajectories could be modeled.

The study of succession has traditionally been dominated by plant ecologists. Even though plant–animal and, to a lesser extent, plant–microbial interactions have been in vogue for much of the time span of successional studies, relatively few workers have considered these in the context of succession. Of course, one notable exception is in the practical management of plant succession by the larger herbivores, which has also attracted scientific rigor (e.g., Gibson and Brown, 1992). Successional interactions with other less conspicuous organisms, namely invertebrates and microorganisms, have been given far lower priority by ecologists. Once these interactions become more complex, by involving other organisms or trophic levels, priority has fallen even further. In the few studies that do exist, interest has focused on the interactions that can be seen, namely those between organisms associated with above-ground plant structures. Include soil organisms and there is a gaping void in our knowledge!